Mine are on a 350F but it looks like they would bolt right on a 550 and work correctly with no interference. They are made from a pair of shifters from salvaged '83 Interceptors. Of course, I used the brake (right) side peg on the right side so it would fold correctly. I kept a stub of the original brake pedal so the return spring would still work. The added bonus is that the rear brake light switch can still be used. It took a little bit of cutting, bending and welding on the shifters and linkage, but I like my rearsets better than any I could have bought.